Ripple Runner Deluxe is a fantastic free rhythm-based autorunner

Rhythm-based autorunning platformer Ripple Runner Deluxe takes its obvious inspiration from Gaijin Games' excellent Bit.Trip Runner, but it successfully builds off that template with its own unique ideas.

Ripple Runner Deluxe is easy to learn, but hard to master. It's also free and browser-based, so give it a go and watch your productivity plummet.

Developed entirely by DDRKirby(ISQ) in a scant 48 hours for Ludum Dare 29 - a game jam beholden to the theme "Beneath the Surface" - Ripple Runner Deluxe's most novel mechanic is that you control two symmetrical avatars: one solid running above the surface, the other a rippled reflection below. Only the solid avatar can take damage, however, and at any time you can flip the two and suddenly the the upper half of the screen is occupied by the reflection, while the concrete figure is inverting gravity below. Additionally, there's an option to flip which side of the surface you're running on to avoid spikes.

It sounds simple and the minimalist graphics don't even begin to do Ripple Runner Deluxe justice, but the real draw is the music: an energetic collection of chiptunes that flow effortlessly with the sound effects tied to each action. Every time you swap places with your reflection it lets out a melodic punch and every skip across narrowly avoided spikes is triumphantly tethered to a series of sprightly sounds.

The levels suddenly alter their properties at various checkpoints, too, as gravity becomes heavier or floatier at different intervals, making for some freewheeling nighttime escapades or tense, industrial skirmishes. Given the limitations Ripple Runner Deluxe was developed under, it's shockingly varied and elegant.